From a01c24e8c591985b9aa17a8a1984b517541ef3be Mon Sep 17 00:00:00 2001 From: Bryan Huh Date: Sun, 15 Nov 2015 18:02:11 -0800 Subject: avformat/aviobuf: Improve readability of aviobuf (Add comments and docs) Signed-off-by: Michael Niedermayer --- libavformat/avio.h | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) (limited to 'libavformat/avio.h') diff --git a/libavformat/avio.h b/libavformat/avio.h index 06dd7f5ef8..abe13b2719 100644 --- a/libavformat/avio.h +++ b/libavformat/avio.h @@ -122,6 +122,53 @@ typedef struct AVIOContext { * to any av_opt_* functions in that case. */ const AVClass *av_class; + + /* + * The following shows the relationship between buffer, buf_ptr, buf_end, buf_size, + * and pos, when reading and when writing (since AVIOContext is used for both): + * + ********************************************************************************** + * READING + ********************************************************************************** + * + * | buffer_size | + * |---------------------------------------| + * | | + * + * buffer buf_ptr buf_end + * +---------------+-----------------------+ + * |/ / / / / / / /|/ / / / / / /| | + * read buffer: |/ / consumed / | to be read /| | + * |/ / / / / / / /|/ / / / / / /| | + * +---------------+-----------------------+ + * + * pos + * +-------------------------------------------+-----------------+ + * input file: | | | + * +-------------------------------------------+-----------------+ + * + * + ********************************************************************************** + * WRITING + ********************************************************************************** + * + * | buffer_size | + * |-------------------------------| + * | | + * + * buffer buf_ptr buf_end + * +-------------------+-----------+ + * |/ / / / / / / / / /| | + * write buffer: | / to be flushed / | | + * |/ / / / / / / / / /| | + * +-------------------+-----------+ + * + * pos + * +--------------------------+-----------------------------------+ + * output file: | | | + * +--------------------------+-----------------------------------+ + * + */ unsigned char *buffer; /**< Start of the buffer. */ int buffer_size; /**< Maximum buffer size */ unsigned char *buf_ptr; /**< Current position in the buffer */ -- cgit v1.2.3